DAVIS COUNTY — Deer are flying through the sky well before Christmas this year.
Instead of pulling Santa on a sleigh, though, they’re blindfolded, restrained and airlifted in orange bags to Fielding Garr Ranch on Antelope Island, where biologists and a team of other staff with the Utah Division of Wildlife Resources check various aspects of each animal’s health.
They’re also mule deer, a bit smaller than their reindeer cousins.
In addition to assessing each individual animal’s health, DWR staff also get a feel for the health status of the island’s mule deer population as a whole.
Starting Monday and continuing through Wednesday if necessary, the DWR team hopes to capture 50 mule deer out of a population of 400-500 on Antelope Island, which is at a healthy size, according to Eric Anderson, district wildlife biologist over the northern region with DWR.
The goal is to maintain a population size that the island can sustain, given vegetation conditions and deer migration on and off the island.
DWR staff, and wildlife biologists with Antelope Island State Park, don’t have to intervene too much, Anderson said, but they try to keep the population from going to high or low — though they don’t kill animals, Anderson said.
“Mother Nature is real good at taking care of herself, but my job as a biologist is trying to reduce the amplitude of how many die,” Anderson said. “... If (the population gets) too high, you’ll see a real steep die-off.”
When the deer are brought in by helicopter, usually in pairs but occasionally in groups of three, teams of several people assess each deer’s weight, hind feet, body length and the fat on the deer’s body, Anderson said.
“The fat helps us understand how well they’re going into winter,” Anderson said. “For mule deer, their survival depends highly on how much fat they can put on during the summer, so that gives us an indication of how well ... the summer has been for them coming into winter.”
They also draw blood to analyze and give the animals shots, including some Vitamin D, Anderson said.
Many of the deer are also given tracking collars.
These collars allow biologists to track the animal’s movements — or even tell if an animal has died. When a collar stops moving, staff often retrieve it and assess the cause of death of the animal.
The collars also provide information about mule deer migration patterns, Anderson said.
For this project — the first with mule deers on Antelope for about five years — they aim to place collars on 30 mule deer, 10 male and 20 female.
Before the deer are airlifted, assessed, and given a collar, they need to be caught.
The state contracts with a company called Heliwild that pursues the animals by helicopter, capturing them by shooting a net out of a gun, entangling the animal.
“It takes a lot of skill,” said Mark Hadley, northern region outreach manager for DWR. “To be able to fly low level like that and to stay over the animal and to shoot that gun ... where it flies out of the helicopter and entangles an animal that’s on the run ... those guys, they’re highly trained. They’re really good at what they do.”
When the animal is captured, Heliwild staff quickly restrain the animal, which reduces its stress, Anderson said.
The animal’s stress is monitored throughout the process. When deer are being assessed, staff measure their temperature, which is usually around 104 degrees Fahrenheit.
If the temperature starts to rise, they know the animal is stressed.
When an animal temperature rises too much, the team will spray it down with an alcohol-water solution, which cools it down, or they’ll cover the deer with a towel soaked in ice water.
Deer can also be injured during their capture.
One buck had lost several teeth, probably in the process of being captured. The teeth were hanging out of its mouth.
It’s possible that the buck had sustained the injury from another buck because it’s currently mule deer mating season, called the rut, when bucks regularly fight with each other.
Despite these injuries, Anderson says that using a helicopter and net gun is the best method to capture the mule deer.
“Doing the helicopter is one of the safest ways for the people ... and for the animal,” Anderson said. “Occasionally you do get injuries, but animals are very durable and can sustain a lot of injuries ... most of what we’re seeing might just be hair being scraped off ... (or) scratches.”
The buck who lost teeth received treatment from a veterinarian, as do all animals who sustain injuries, Anderson said.
Projects like this are done all over the state with deer, elk, bison and bighorn sheep, Anderson said — even in the mountains. The projects are most successful in the winter, when animals congregate.
“It’s a pretty intense effort statewide to monitor our populations and look at migration, and that helps us to better be stewards of the wildlife for the citizens of Utah,” Anderson said.